Replace common suspend/resume handling code by generic helper.
Almost no functional change, the only difference is in handling
of hypothetical memory allocation failure on boot.

[snawrocki@kernel.org: Whitespace correction]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sylwester Nawrocki <snawrocki@kernel.org>